1. Field of the Invention
The present invention relates to a static elimination technology, and more particularly, to a static elimination device. The present invention also relates to a cassette in which the static elimination device is installed.
2. Description of the Prior Art
A flat-panel device such as art LCD is an essential display device for an electrical product. During the manufacturing, process of a TFT-LCD (short for Thin Film Transistor-Liquid Crystal Display), static electricity is often produced on the surface of a glass substrate when the glass substrate is brought into contact or friction in different processes. Static electricity on the surface of the glass substrate absorbs particles, causing the particles to be attached to the surface of the glass substrate. As a result, the glass substrate is polluted; or even, an electrostatic discharge (ESD) event might occur. Static electricity also causes static charge accumulation. A huge sudden discharge would occur when electric charges are accumulated to a certain degree. A semiconductor element on the glass substrate would be damaged due to the sudden discharge. Moreover, static electricity might be produced when as cassette where the glass substrate is installed is carried or transported.
To settle the damage caused by static electricity, two methods for eliminating static electricity are used in the LCD panel industry. The first one method is that, devices are grounded and the relative humidity of the environment is adjusted so as to eject static electricity from the surface of the object. Or, ions are sprayed on the surface of the glass substrate using an electrostatic neutralizer for eliminating static electricity. The second one method is that, four to six rod-like electrostatic neutralizers installed on the four corners of the outside of the cassette so that every glass substrate layered in the cassette could obtain the sprayed ions from the nozzles of the electrostatic neutralizers. However, the above-mentioned methods have shortcomings:
1. The electrostatic neutralizers are vertically disposed on the four comers of the cassette. The legs of the electrostatic neutralizers may hinder the nozzles of the electrostatic neutralizers from effectively spraying ions on the surface of the glass substrate.
2. The glass substrate is layered inside the cassette. The glass substrate could only obtain scanty ions sprayed by the electrostatic neutralizers, let alone a large-size glass substrate. To effectively eliminate static electricity on the surface of the large-size glass substrate, a plurality of electrostatic neutralizers are used. However, the increasing electrostatic neutralizers are a burden. Production costs increase because of the periodical renewal of the increasing electrostatic neutralizers and the power consumption of the increasing electrostatic neutralizers.
3. The ions sprayed by the electrostatic neutralizers are obviously affected by the airflow inside the dust-free cavity. The airflow inside the dust-free cavity flows in a specific direction, and the specific direction is often contradictory to the path of the sprayed ions. The to contradiction causes the alternation of some paths of the sprayed ions, thereby impeding the electrostatic neutralizers to eliminate static electricity.